[LINK] BPL

[Robin Whittle]

Hi Stephen,

Your optimism for BPL is like an eerily eternal Energizer Bunny.

An avalanche of facts and considered opinions from me and other folks
who know a lot more about signals, radio frequency propagation,
modulation techniques etc. leaves your optimism unscathed.  Likewise
the lack of this service being deployed on a commercially successful
basis, despite years of development and numerous trials.

If there was some way of surrounding you and your optimism for BPL
with photovoltaic cells or connecting it to an alternator, this would
be a source of everlasting energy.

I have some idea of your frustration with being stuck on dial-up and
I guess your unreasonable optimism for BPL is based on the notion
that there is no other way but BPL to improve broadband in the bush.

Satellite is one way.  Wimax is another.

A promising new field is "white space" in the UHF band - mesh
networks carefully using UHF TV channel frequencies far from where
those frequencies are actually used.

http://www.google.com/search?hl=en&as_q=UHF&as_epq=white+space


BPL gear has been built and the technical standards for it are in a
very early stage of development.  It is difficult or impossible to
make worldwide standards since the powerline distribution structure
in the USA and other 110 to 120V countries is completely different to
that in the 220 to 240 volt countries.  Also, the conditions are
radically different for overhead and for underground cables.

That BPL gear is about as technically advanced as it ever could be,
since it uses the best modulation techniques and presumably some
protocols well suited to the requirements.

You can connect two of the things in close proximity and then get
their so-called "200 Mbps" data rate.  But the real data rate is a
lot less, due to noise, distortion, protocol overhead, forward error
correction etc. and the switching times between upstream and
downstream usage of the frequencies.

What no-one can do is deploy these boxes on real powerlines to
achieve real broadband performance.

If BPL at real broadband speeds was physically possible, in a robust,
reliable, cost-effective manner, we would know all about it. There
would be services all over the place.

There aren't and there won't be, because the nature of the cables is
at odds with what would be required for that to happen.


> Agreed :)
> 
> And, far be it for ME to dispute your firmly held theoretical beliefs.

The absence of broadband BPL services has nothing to do with my
beliefs.  If it was possible, it would be widespread by now.


> Whatever, all these people should be told it's a 'technical impossibility'
> 
> I'm sure they would be fascinated with your mathematical theories/beliefs.
> 
> Thus, let's just agree to disagree for now, guys, amicably and peacefully.
> 
> It takes one too long, over a 48kps dial up, to seek any more info re BPL.

The limitation is not the speed of your connection.  The limitation
is that you want to repeatedly talk-up and promote unreasonable
optimism about a hype-laden technology which has never worked - on a
high-quality public mailing list where it is expected that people who
discuss things are actually interested in learning about the subject
at hand.

You display no evidence of such interest.   So don't be surprised if
I and maybe other folks tend to ignore you in the future, or fail to
go to the trouble we would with other Link people to discuss things
in detail.

  - Robin